Wireshark is a GTK+-based network protocol analyzer that lets you capture and interactively browse the contents of network frames. The goal of the project is to create a commercial-quality analyzer for Unix and Win32 and to give Wireshark features that are missing from closed-source sniffers.
Changes: Wireshark 2.6 is the last release that will support the legacy (GTK+) user interface. It will not be supported or available in Wireshark 3.0. Many user interface improvements have been made.